Blower housing with fluted outlet

ABSTRACT

A heating, ventilating, and air conditioning (HVAC) blower that includes a housing that defines an air inlet, an air outlet, and a passageway therebetween. An airflow may be directed from the air inlet to the air outlet through the passageway. The housing at the air outlet includes an outlet end portion with a plurality of flutes that extend from the passageway.

BACKGROUND

The present disclosure relates generally to environmental control systems, and more particularly, to blower assemblies for environmental control systems.

Environmental control systems are utilized in residential, commercial, and industrial environments to control environmental properties, such as temperature and humidity, for occupants of the respective environments. The environmental control system may control the environmental properties through control of an airflow delivered to the environment. For example, a heating, ventilation, and air conditioning (HVAC) system may route the airflow through a heat exchanger prior to delivery to the environment. Unfortunately, inefficient delivery of the airflow to the heat exchanger may decrease an overall efficiency of the HVAC system.

SUMMARY

The present disclosure relates to a heating, ventilating, and air conditioning (HVAC) blower that includes a housing that defines an air inlet, an air outlet, and a passageway therebetween. An airflow may be directed from the air inlet to the air outlet through the passageway. The housing at the air outlet includes an outlet end portion with a plurality of flutes that extend from the passageway.

The present disclosure also relates to a heating, ventilating, and air conditioning (HVAC) blower that includes a housing that defines an air inlet, an air outlet, and a passageway therebetween. An airflow may be directed from the air inlet to the air outlet through the passageway. The housing at the air outlet includes an outlet end portion, which includes a plurality of flutes that extend from the passageway and a plurality of vortex generators.

The present disclosure further relates to a heating, ventilating, and air conditioning (HVAC) blower that includes a housing that defines an air inlet, an air outlet, and a passageway therebetween. An airflow may be directed along a length from the air inlet to the air outlet through the passageway. The housing at the air outlet includes an outlet end portion, which includes a plurality of flutes and a vortex generator. The passageway extends into the plurality of flutes, and the plurality of flutes extends from an edge of the air outlet a distance of at least 10 percent of the length.

DRAWINGS

FIG. 1 is a schematic of an environmental control system having a blower assembly, in accordance with embodiments of the present disclosure;

FIG. 2 is a side view of an embodiment of the blower assembly and heat exchanger, in accordance with embodiments of the present disclosure;

FIG. 3 is a bottom view of an embodiment of the blower assembly of FIG. 2, in accordance with embodiments of the present disclosure; and

FIG. 4 is a perspective view of an embodiment of a blower housing of the blower assembly, in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

Embodiments of the present disclosure are directed towards improved blower assemblies for heating, ventilating, and air conditioning (HVAC) systems. As will be appreciated, a heat exchanger of an HVAC may affect properties of an airflow directed across the heat exchanger. For example, the heat exchanger may affect the temperature of the airflow, the humidity of the airflow, the air quality of the airflow, or any combination thereof. A blower housing discharges the airflow from a blower towards the heat exchanger. The blower may be an impeller, fan, or similar device that discharges airflow. Features of the blower housing may reduce or eliminate kinetic energy losses of the airflow as the airflow is routed from an inlet of the blower housing to an outlet of the blower housing. For example, the blower housing may enable lateral expansion of the airflow from the inlet to the outlet of the blower housing. Additionally, or in the alternative, features of the blower housing may increase the turbulence of portions or sub-streams of the airflow through the blower housing, thereby increasing the heat transfer coefficient between the respective portions of the airflow and the heat exchanger downstream of the blower housing. For example, a fluted outlet of the blower housing may increase streamwise vorticity generation of the airflow toward the heat exchanger. In some embodiments, vortex generating structures of the blower housing may generate vortices in the airflow, thereby increasing the turbulence of the airflow. Accordingly, one or more features of the blower housing may increase the efficiency of the HVAC system by increasing the heat transfer coefficient between the respective portions of the airflow and the heat exchanger downstream of the blower housing. Increased efficiency of the HVAC system may enable a given HVAC load to be satisfied with reduced operating costs, the given HVAC load to be satisfied by elements of the HVAC system that are smaller than a conventional HVAC system, the HVAC load capability of the HVAC system may be increased for a given operating cost, or any combination thereof.

Turning now to the drawings, FIG. 1 is a schematic of a heating, ventilating, and air conditioning system 10 having a blower assembly 12, in accordance with present embodiments. A heat exchange system 14 of the HVAC system 10 controls a temperature of a fluid through a heat exchanger 16 to control environmental properties of an airflow 18 routed across the heat exchanger 16. The environmental properties of the airflow include temperature, humidity, and air quality. The airflow 18 may be routed to a load 20 to affect the environmental properties of the load 20. In some embodiments, at least a portion 22 of the airflow 18 is drawn from the load 20 to an air intake 24. Optionally, the air intake 24 may receive one or more external airflows, as shown by the dashed arrows 26.

The heat exchange system 14 may include, but is not limited to, a furnace, a heat pump, a boiler, or other system that may supply a fluid to the heat exchanger 16. The heat exchanger 16 may transfer heat to the airflow 18 or extract heat from the airflow 18. For example, the heat exchange system 14 may be a heat pump configured to transfer heat from an external environment 28 to the load 20 via the heat exchanger 16, the heat exchange system 14 may be a heat pump configured to transfer heat from the load 20 to the external environment 28 via the heat exchanger 16, or any combination thereof. Moreover, a furnace or a boiler of the heat exchange system 14 may use energy from an external source to heat a fluid routed through the heat exchanger 16 to transfer heat to the load 20. For example, an electric furnace or electric boiler may use electricity to add heat to the airflow 18. In some embodiments, a combustion furnace or combustion boiler may add heat to the airflow 18 via combustion of a fuel, such as natural gas, liquefied petroleum gas, propane, heating oil, coal, or wood. In some embodiments, the heat exchange system 14 may supply steam or heated water via the heat exchanger 16 to increase a temperature and humidity of the airflow 18.

The airflow 18 is routed from the air intake 24 to the blower assembly 12. A blower 30 of the blower assembly 12 receives the airflow 18 and routes the airflow 18 to a heat exchange duct 32 via a blower housing 34. A motor 36 coupled to the blower 30 drives the blower 30 to increase the energy of the airflow 18. The blower 30 may increase the energy of the airflow 18 by increasing the velocity of the airflow 18, the pressure of the airflow 18, or increasing both the velocity and the pressure of the airflow 18. In some embodiments, the blower 30 receives the airflow 18 from the air intake 24 along an axis 38 and routes the airflow 18 in a direction other than along the axis 38. For example, where the blower 30 is a centrifugal fan such as depicted in FIGS. 2, 3, and 4, the centrifugal fan receives the airflow 18 along the axis 38, and blades of the centrifugal fan rotate about the axis 38 of rotation to drive the airflow 18 in a radial direction relative to the axis 38. The airflow 18 may then be directed from the centrifugal fan in a substantially tangential direction. In some embodiments, the blower 30 is a centrifugal fan with a forward curved impeller, a centrifugal fan with a backward curved impeller, or centrifugal fan with a radial impeller.

As discussed in detail below, the blower housing 34 may receive the airflow 18 from the blower 30 at one or more air inlets 60 and route the airflow 18 toward the heat exchange duct 32 through an air outlet 40. The blower housing 34 defines the air inlet 60, the air outlet 40, and a passageway therebetween the air inlet 60 and the air outlet 40. For example, the blower housing 34 may receive the airflow 18 along the axis 38 via the inlet 60, direct the airflow through the passageway of the blower housing 34 in a radial direction from the axis 38 and in a circumferential direction about the axis 38, and discharge the airflow 18 in a different direction than along the axis, such as tangential to the axis 38 via the outlet 40. It may be appreciated that embodiments of the blower 30 with a single air inlet 60 may be referred to as a single wide, single inlet blower. In some embodiments, a double wide, double inlet blower has two air inlets 60 that are arranged opposite one another, and one outlet 40. While the discussion herein may refer to embodiments of the blower 30 with the single air inlet 60, it may be appreciated that the features of the outlet 40 and outlet end portion, such as flutes and vortex generators, may be applied to embodiments of the blower with two air inlets 60. As discussed herein, the direction that the outlet 40 discharges the airflow 18 is referred to as a downstream direction 81. In some embodiments, the outlet 40 is coupled to the heat exchange duct 32. Additionally, or in the alternative, the outlet 40 of the blower housing 34 is disposed within the heat exchange duct 32. As discussed in detail below, a width of the outlet 40 may be greater than a width of the inlet 60. Moreover, features of the blower housing 34 as explained below may affect how the airflow 18 is discharged from the outlet 40.

It may be appreciated, that in some embodiments, the blower assembly 12 with the blower housing 34, the blower 30, and the motor 36 may be arranged or packaged together for modular installation between the intake 24 and the heat exchange duct 32. Accordingly, although the elements described herein may be sized according to design conditions of the load 20 and other equipment of the HVAC system 10, embodiments of the blower assembly 12 described herein may facilitate increased efficiency of the HVAC system 10 without increasing the size of the blower assembly 12. That is, embodiments of the blower assembly 12 described herein may be configured for a retrofit with a pre-existing HVAC system. In some embodiments, a filter 42 is coupled to the intake 24 or is disposed within the blower assembly 12.

A controller 44 of the HVAC system 10 may monitor and control operation of the HVAC system 10. One or more sensors 46 coupled to the controller 44 may provide feedback regarding environmental properties (temperature, humidity, air quality, etc.) of load 20, the external environment 28, the blower assembly 12, or the heat exchange duct 32, or any combination thereof. A processor 48 of the controller 44 may execute instructions (e.g., software code) stored in a memory 50 to monitor and control elements of the HVAC system 10. In some embodiments, the controller 44 controls the speed of the airflow 18 and/or the volumetric output of the airflow 18 from the blower 30 through control of the motor 36. In some embodiments, the controller 44 controls the heat exchange system 14 to control the temperature and/or flow rate of a fluid through the heat exchanger 16. The fluid through the heat exchanger may be air, water, steam, or a refrigerant, or any combination thereof. The controller 44 may control operation of elements of the HVAC system 10 based at least in part on environmental properties of the load 20 and the external environment 28.

FIG. 2 is a view of an embodiment of the blower assembly 12 with the axis 38 being directed perpendicular to the view and heat exchanger 16 of the HVAC system 10, in accordance with embodiments of the present disclosure. The blower 30 may receive the airflow 18 from the air intake 24 via the blower inlet 60. As discussed above, the blower 30 may be a centrifugal fan that receives the airflow 18 in an axial direction 62 along the blower axis 38 of rotation through the blower inlet 60. Blades 64 of the blower 30 drive the airflow 18 in a radial direction 66 from the axis 38 of rotation toward the blower housing 34. The blades 64 may be mounted to a shaft 68 coupled to the motor 36 discussed above. The motor 36 drives the shaft 68 and the blades 64 of the blower 30 in a circumferential direction 70, thereby increasing the pressure and/or the velocity of the airflow 18. The blades 64 of the blower also drive the airflow 18 in the circumferential direction 70 about the axis 38 toward the outlet 40. The blades 64 shown in FIG. 2 are forward curved blades 64, although other embodiments of the blower 30 may have backward curved blades or radial blades.

The airflow 18 is driven in the radial direction 66 by the blades 64 of the blower 30. The blower housing 34 has a body 58 with an interior structure 74 and an exterior structure 75. The body 58 of the blower housing 34 is a wall that defines the passageway between the inlet 60 and the outlet 40. The structures 74 and 75 are disposed about the axis 38 and the blower 30. In some embodiments, the interior structure 74 has one or more openings circumferentially disposed about the axis 38 to facilitate receipt of the airflow 18 in the radial direction 66 from the blades 64 to an interior 86 of the blower housing 34. The interior structure 74 nearest the blades 64 of the blower 30 may be referred to herein as a cutoff 72. The passageway from the inlet 60 to the outlet 40 extends through the interior 86 of the blower housing 34. That is, the passageway is the space defined by the blower housing 34 through which the airflow 18 is directed from the air inlet 60 to the air outlet 40.

The blower housing 34 may have a scroll-shape that generally spirals outward from the axis 38. That is, the body 58 of the blower housing 34 extends circumferentially about the axis 38 of rotation from the cutoff 72 to the outlet 40. It may be appreciated that the passageway through the interior 86 is curved at least partially circumferentially about the axis 38 of rotation. The cutoff 72 is disposed a first distance 52 from the axis 38, and the outlet 40 is disposed a second distance 54 from the axis 38. The body 58 extends circumferentially about the axis 38 such that the second distance 54 is greater than the first distance 52. A radial depth 76 of the blower housing 34 in the radial direction 66 may increase from the cutoff 72 to the outlet 40. Accordingly, a first cross-sectional area 78 of the interior 86 of the blower housing 34 nearer the cutoff 72 is less than a second cross-sectional area 80 of the interior 86 of the blower housing 34 nearer the outlet 40. The cross-sectional area of the interior 86 of the blower housing 34 may increase continuously or step-wise along the circumferential length of the body 58 from the cutoff 72 to the outlet 40. The cross-sectional areas 78, 80 and the outlet 40 may have similar shapes despite the larger size and cross-sectional area of the outlet 40. For example, the cross-sectional areas 78, 80 and the outlet 40 may be generally circular, elliptical, ovular, or rectangular. Rounded shapes for the outlet 40 may reduce or eliminate the vortices and swirling effects that may be associated with outlets having square or rectangular shapes. As discussed below, embodiments of the outlet 40 of the blower housing 34 may be generally square or rectangular shaped with flutes and ridges that have rounded corners at the outlet 40. As discussed in detail below, in some embodiments, an axial width of the blower housing 34 increases from the cutoff 72 to the outlet 40. Additionally, or in the alternative, the axial width of the blower housing 34 at the outlet 40 may be greater than a width of the inlet 60 across the axis 38. This increasing axial width of the blower housing 34 at the outlet may enable lateral expansion of the airflow 18 into the heat exchange duct 32, may increase the kinetic energy recovery of the blower assembly 12, and may reduce pressure losses from the blower housing 34 relative to a conventional blower housing.

The blower assembly 12 may change the direction of the airflow 18. As shown in FIG. 2, the airflow 18 may enter the blower 30 of the blower assembly 12 in the axial direction 62, and the outlet 40 of the blower assembly 12 may discharge the airflow 18 in the downstream direction 81. The downstream direction 81 may be substantially perpendicular (e.g., within 10 degrees of perpendicular) to both the axis 38 and the axial direction 62. The blower housing 34 may route the airflow 18 in the radial direction 66 from the blower 30, and the blower housing 34 may route the airflow 18 in the circumferential direction 70 from the inlet 60 to the outlet 40 through passageway of the interior 86 of the body 58. The outlet 40 discharges the airflow 18 in the tangential direction 83, such as in the downstream direction 81, toward the heat exchanger 16. Vorticity within the airflow 18 may increase the heat transfer coefficient between the heat exchanger 16 and the airflow 18, thereby increasing the heat transfer between the airflow 18 and a fluid 85 through the heat exchanger 16. In some embodiments, the blower housing 34 may increase the vorticity of portions (e.g., sub-streams) of the airflow 18.

In some embodiments, the blower housing 34 may have one or more vanes that extend in the circumferential direction 70. Dashed lines 82 of FIG. 2 show the radial extent of optional vanes extending from the interior structure 74 and the exterior structure 75 into the passageway of the body 58. The vanes extend from an interior surface 83 of the body 58 radially into the interior 86 of the blower housing 34. In some embodiments, the vanes may form sub-streams within the airflow 18 that may increase mixing within the respective streams. The one or more vanes may provide structural support for the blower housing 34. Where the blower housing 34 has vanes, the vanes may extend into the passageway of the blower housing 34 from all interior surfaces 83 of the blower housing 34. In some embodiments, the vanes may extend into the interior 86 of the blower housing 34 from only the interior structure 74 or only the exterior structure 75. In some embodiments, the vanes may be extensions of ridges discussed in detail below.

Additionally, or in the alternative, the blower housing 34 may have one or more vortex generators 88 that extend from the interior surfaces 83 into the passageway through the interior 86 of the blower housing 34. The vortex generators 88 may partially obstruct the airflow 18, thereby inducing eddies 90, swirls, and vortices in the airflow 18 downstream of the outlet 40 in the direction 81. In some embodiments, the vortex generators 88 may be positioned at an outlet end portion 92 of the blower housing 34. The outlet end portion 92 may be approximately 1, 2, 3, 4, or 5 inches from an edge 94 of the outlet 40. Additionally, or in the alternative, the outlet end portion 92 may extend less than approximately 10, 5, or 3, 2, or 1 percent of a circumferential length of the passageway through the blower housing 34 from the cutoff 72 to the outlet 40.

In some embodiments, the outlet 40 of the blower housing 34 is coupled to an outlet flange 96. The outlet flange 96 couples the blower assembly 12 to the heat exchange duct 32. As discussed in detail below, the outlet 40 may have an irregular or non-convex perimeter. In some embodiments, the outlet flange 96 enables the outlet 40 to be coupled to a conventional heat exchange duct 32 with a reduced or minimal effect on the turbulence of the airflow 18 discharged from the outlet 40. Additionally, or in the alternative, the outlet flange 96 may enable the outlet 40 to be centered in one or more directions (e.g., the axial direction 62, a lateral direction 98) relative to the heat exchanger 16.

FIG. 3 is a bottom view of the blower housing 34, taken along line 3-3 of FIG. 2. As described above, an axial width 110 of the cutoff 72 of the blower housing 34 may be less than an outlet axial width 112 of the outlet 40 of the blower housing 34. The axial width 110 and the outlet axial width 112 extend along the axial direction 62. This increased outlet axial width 112 of the blower housing 34 relative to the axial width 110 may enable lateral expansion of the airflow 18 within the blower housing 34 along an expansion axis 114. The expansion axis 114 may be substantially parallel with the axial direction 62. As utilized herein, the term “substantially” may be understood to be within 10 percent of the stated value. Lateral expansion of the airflow 18 along the expansion axis 114 may increase kinetic energy recovery of the airflow 18, thereby reducing energy losses of the blower assembly 12 from the blower housing 34. In some embodiments, the axial width 110 is between approximately 40 to 95, 50 to 80, or 60 to 75 percent of the outlet axial width 112. In some embodiments, the passageway through the body 58 from the cutoff 72 to the outlet 40 is aligned along a common centerline 116 in the direction 81, thereby increasing uniformity of the lateral expansion along the expansion axis 114 on each side of the centerline 116.

The vortex generators 88 may be oriented at an angle 118 relative to the downstream direction 81, such as between approximately 1 to 60 degrees, 10 to 45 degrees, or 15 to 30 degrees. FIG. 3 illustrates a row of vortex generators 88 in phantom at the outlet end portion 92. In some embodiments, each vortex generator 88 is skewed with the same angle relative to the downstream direction 81. The vortex generators 88 may be disposed around a perimeter (e.g., top, bottom, sides) of the outlet 40. In some embodiments, each vortex generators 88 may be skewed relative to the downstream direction 81 differently based at least in part on where the respective vortex generator 88 is disposed. For example, the vortex generators 88 on the bottom of the outlet 40 may be skewed differently than the vortex generators 88 on the sides or top of the outlet 40.

In addition to or in the alternative to the increased outlet width 112 of the blower housing 34, features of the blower housing 34 may affect flow characteristics (e.g., vorticity, mixing) of the airflow 18 discharged from the outlet 40. FIG. 4 illustrates an embodiment of the blower housing 34 in which the outlet 40 has a perimeter 136 that is corrugated (e.g., fluted, grooved, lobed, ridged, wavy, castellated). The corrugated perimeter 136 of the outlet 40 may have ridges 130 that extend radially into the passageway through the interior 86 of the blower housing 34. Adjacent ridges 130 may form flutes 132 in the outlet 40. The flutes 132 may be grooves, recesses, channels, trenches, or hollows that extend from the passageway of the blower housing 34. That is, the flutes 132 are open to the passageway through the interior 86 of the blower housing 34. The corrugated perimeter 136 of the outlet 40 may increase the lateral expansion and/or the streamwise vorticity of the discharged airflow 18 regardless of whether the outlet width 112 is greater than an axial width 110. In some embodiments, the corrugated perimeter 136 has ridges 130 and flutes 132 that are sinusoidal with rounded edges. In some embodiments, the corrugated perimeter 136 has ridges 130 and flutes 132 that are angular with cornered edges (e.g., square, triangle, saw tooth). The ridges 130 and flutes 132 may be substantially aligned with the downstream direction 81 from the outlet 40. In some embodiments, the vanes discussed above may be substantially aligned with the downstream direction 81. As discussed below, some embodiment of the perimeter 136 of the outlet 40 may have lengths of the edge 94 that are smooth without ridges 130 or flutes 132. For example, the top and bottom of the edge 94 of the outlet 40 may have flutes 132, and the sides of the edge 94 of the outlet 40 may not have flutes 132. In some embodiments, the flutes 132 are disposed on at least 10, 25, 50, or 75 percent or more of a surface of the blower housing 34 that defines the air outlet 40.

The ridges 130 of the blower housing 34 may separate portions of the airflow 18 through the outlet 40 into sub-streams 134 discharged from the blower housing 34 through the flutes 132. That is, the flutes 132 may receive sub-streams 134 of the airflow 18. The sub-streams 134 of the airflow 18 discharged from the blower housing 34 may increase streamwise vorticity and mixing of the airflow 18 downstream of the outlet 40, thereby increasing the convective heat transfer between the airflow 18 and the heat exchanger 16. In some embodiments, the flutes 132 of the perimeter 136 of the outlet 40 enable swirling or vortices of sub-streams 134 of the airflow 18 to persist downstream of the outlet 40 longer than an outlet without the flutes. While the outlet 40 of FIG. 4 illustrates the corrugated perimeter 136 with a non-convex perimeter, it may be appreciated that other non-convex perimeter shapes may facilitate formation of sub-streams 134 of the airflow 18 from the outlet 40. The corrugated perimeter 136 of the outlet 40 increases the perimeter area of the outlet relative to a circular, elliptical, or ovular shaped outlet with the same cross-sectional area.

The ridges 130 and flutes 132 of the corrugated perimeter 136 may be disposed on sides 138 of the outlet 40, on a bottom 140 of the outlet 40, a top 142 of the outlet 40, or any combination thereof In some embodiments, the ridges 130 and flutes 132 of the blower housing 34 may be disposed only on the interior surface 83 of the blower housing 34, such that an exterior surface 84 of the blower housing 34 does not have ridges or flutes. Furthermore, a spacing 144 between the ridges 130 and flutes 132 may be uniform or may vary about the perimeter 136. Additionally, or in the alternative, a depth 146 of the ridges 130 and flutes 132 may be uniform or may vary about the perimeter 136 of the blower housing 34 that defines the outlet 40. For example, some embodiments of the outlet 40 may have more and/or deeper flutes 132 at the top 142 of the outlet 40 than at the bottom 140 of the outlet 40. Non-uniform distribution of the ridges 130 and flutes 132 may increase the convective heat transfer of some sub-streams 134 of the airflow 18 discharged from the outlet 40. In some embodiments, the one or more vanes discussed above are extensions of ridges 130 that extend into the passageway of the blower housing 34. Accordingly, adjustments to the disposition and sizing of the ridges 130 and flutes 132 about the perimeter 136 of the outlet 40 may enable the blower housing 34 to increase the downstream convective heat transfer between the airflow 18 and the heat exchanger 16. In some embodiments, the body 58 is disposed about the axis 38 such that the cutoff 72 extends through part of the interior surface 83 of the bottom 140 of the outlet 40, as shown in FIG. 4. In some embodiments, the outlet 40 is disposed radially further from the axis 38 than the cutoff 72 such that the ridges 130 and flutes 132 at the bottom 140 of the outlet 40 are not abbreviated by the cutoff 72.

The ridges 130 and flutes 132 of the corrugated perimeter 136 may be disposed at the outlet end portion 92 of the blower housing 34. In some embodiments, the vortex generators 88 described with FIG. 2 may be disposed at the outlet end portion 92 with the ridges 130 and flutes 132. In some embodiments, the vortex generators 88 are deflectors arranged between ridges 130 that extend into the passageway to obstruct sub-streams 134 of the airflow 18 discharged through the flutes 132. The ridges 130 of the corrugated perimeter 136, the flutes 132 of the corrugated perimeter 136, or both the ridges 130 and the flutes 132 of the corrugated perimeter 136 may extend along the interior surfaces 83 beyond the outlet end portion 92 along the body 58 of the blower housing 34 toward the cutoff 72. For example, the ridges 130 and flutes 132 may extend circumferentially along approximately 10, 25, 50, 75 or 100 percent of the body 58 from the edge 94 of the outlet 40 to the cutoff 72. Extending the flutes 132 beyond the outlet end portion 92 towards the cutoff 72 may increase turbulence of sub-streams 134 discharged from the outlet 40, thereby increasing the convective heat transfer with the heat exchanger 16 downstream of the outlet 40.

The blower housing 34 may be formed from a variety of materials including, but not limited to, aluminum, steel, plastics, and composite materials. Plastics that may form the blower housing 34 may include, but are not limited to, high density polyethylene (HDPE), polyvinyl chloride (PVC), polypropylene, polycarbonate, and polyurethane. In some embodiments, the blower housing 34 may be a unitary structure from the inlet 60 to the outlet 40. That is, the blower housing 34 may be a one-piece or integral structure from the inlet 60 to the outlet 40. Embodiments of the unitary blower housing may be formed as an integral structure or joined together by a fusion process (e.g., welding). In some embodiments, the blower housing 34 is formed by a molding process (e.g., split mold, injection mold, compression mold, vacuum mold). For example, the blower housing 34 may be a unitary plastic structure formed by a molding process. In some embodiments, the ridges 130, the flutes 132, or any combination thereof may be formed with the blower housing 34. That is, the flutes 132 may be integrally formed with the blower housing 34. For example, the ridges 130 and flutes 132 may be molded into the sides 138, bottom 140, and top 142 of the blower housing 34. In some embodiments, the flutes 132 of the blower housing 34 may be formed by a material removal process, such as cutting, machining, or etching. Additionally, or in the alternative, the ridges 130 may be formed by an additive material process, such as welding or an adhesive. In some embodiments, the outlet end portion 92 is formed separately from the blower housing 34 and is coupled to the outlet 40 of the blower housing 34 for installation with the blower assembly 12. The outlet end portion 92 may include vortex generators 88 alone or in combination with the flutes 132.

Technical effects of the blower housing described herein may include reduced pressure losses of the airflow through the blower housing, increased heat transfer downstream of the blower housing between the airflow and the heat exchanger, or any combination thereof. Lateral expansion of the airflow based at least in part on the wider outlet of the blower housing may increase pressure recovery of kinetic energy from the blower housing. The lateral expansion of the airflow may increase the uniformity of a velocity profile of the airflow from the outlet of the blower housing. Outlet features (e.g., ridges, flutes, and vortex generators) may increase streamwise vorticity of sub-streams of the airflow, thereby increasing the mixing of the airflow itself. Increased mixing of the airflow may increase the heat transfer between the airflow and the heat exchanger downstream of the blower housing outlet. Increased efficiency of the blower housing described herein may enable a smaller blower housing to have the same capability as a larger conventional blower housing. Additionally, or in the alternative, increased efficiency of the blower housing described herein may enable a greater capacity (e.g., volume, velocity) airflow through the blower housing without increasing the power to drive the airflow relative to a convention blower housing.

While only certain features and embodiments have been illustrated and described, many modifications and changes may occur to those skilled in the art (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters (e.g., temperatures, pressures, etc.), mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure. Furthermore, in an effort to provide a concise description of the exemplary embodiments, all features of an actual implementation may not have been described (i.e., those unrelated to the presently contemplated best mode, or those unrelated to enablement). It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation. 

1. A heating, ventilating, and air conditioning (HVAC) blower, comprising: a housing which defines an air inlet, an air outlet, and a passageway therebetween through which an airflow may be directed from the air inlet to the air outlet, wherein the housing at the air outlet comprises an outlet end portion with a plurality of flutes that extend from the passageway.
 2. The HVAC blower of claim 1, wherein the blower comprises an impeller that rotates about an axis of rotation to direct the airflow from the air inlet to the air outlet, wherein the passageway is curved at least partially circumferentially about the axis of rotation.
 3. The HVAC blower of claim 1, wherein the air inlet comprises an inlet width and the air outlet comprises an outlet width, wherein the air outlet width is greater than the air inlet width.
 4. The HVAC blower of claim 1, wherein the outlet end portion of the air outlet is generally rectangular in shape.
 5. The HVAC blower of claim 1, wherein the flutes are integrally formed with the outlet end portion.
 6. The HVAC blower of claim 5, wherein the housing is molded.
 7. The HVAC blower of claim 1, wherein the housing is formed of a unitary piece.
 8. The HVAC blower of claim 1, wherein the outlet end portion is corrugated to form the plurality of flutes.
 9. The HVAC blower of claim 1, wherein the passageway comprises a length, and the plurality of flutes extends from an edge of the air outlet a distance of at least 10 percent of the length.
 10. The HVAC blower of claim 1, wherein the housing comprises vanes that extend into the passageway.
 11. The HVAC blower of claim 10, wherein the plurality of flutes is aligned with a direction of the airflow through the passageway and the air outlet, and at least some of the vanes are aligned with the plurality of flutes in the direction of the airflow.
 12. The HVAC blower of claim 1, wherein the outlet end portion comprises a vortex generator.
 13. The HVAC blower of claim 12, wherein the vortex generator comprises a deflector that extends from the housing into the passageway.
 14. The HVAC blower of claim 13, wherein the plurality of flutes is aligned with a direction of the airflow through the passageway and the air outlet, and the deflector is oriented at an angle relative to the direction of the airflow.
 15. The HVAC blower of claim 14, wherein the vortex generator is disposed within a flute of the plurality of flutes, and the vortex generator is configured to obstruct a sub-stream of the airflow in the direction through the flute of the plurality of flutes.
 16. A heating, ventilating, and air conditioning (HVAC) blower, comprising: a housing which defines an air inlet, an air outlet, and a passageway therebetween through which an airflow may be directed from the air inlet to the air outlet, wherein the housing at the air outlet comprises an outlet end portion, and the outlet end portion comprises: a plurality of flutes that extend from the passageway; and a plurality of vortex generators.
 17. The HVAC blower of claim 16, wherein the blower comprises an impeller that rotates about an axis of rotation to direct airflow from the air inlet to the air outlet, wherein the passageway is curved at least partially circumferentially about the axis of rotation.
 18. The HVAC blower of claim 16, wherein the plurality of flutes is aligned with a direction of the airflow through the passageway and the air outlet, and at least some of the plurality of vortex generators are oriented at an angle relative to the direction of the airflow.
 19. The HVAC blower of claim 18, wherein the plurality of vortex generators comprises deflectors that extend from the housing into the passageway.
 20. The HVAC blower of claim 16, wherein the plurality of flutes are disposed on at least 50 percent of a surface of the blower housing that defines the air outlet.
 21. The HVAC blower of claim 16, wherein the housing is molded.
 22. The HVAC blower of claim 16, wherein the air inlet comprises an inlet width and the air outlet comprises an outlet width, wherein the air outlet width is greater than the air inlet width.
 23. A heating, ventilating, and air conditioning (HVAC) blower, comprising: a housing which defines an air inlet, an air outlet, and a passageway therebetween through which an airflow may be directed along a length from the air inlet to the air outlet, wherein an outlet end portion of the housing at the air outlet comprises a plurality of flutes and a vortex generator, wherein the passageway extends into the plurality of flutes, and the plurality of flutes extends from an edge of the air outlet a distance of at least 10 percent of the length.
 24. The HVAC blower of claim 23, wherein the blower comprises an impeller that rotates about an axis of rotation to direct airflow from the air inlet to the air outlet, wherein the passageway is curved at least partially circumferentially about the axis of rotation.
 25. The HVAC blower of claim 23, wherein the housing is formed of a unitary piece.
 26. The HVAC blower of claim 23, wherein the outlet end portion is corrugated to form the plurality of flutes. 